Universal grinding machines, which can be used not only for the circular grinding and surface grinding of metal workpieces, but which can also be used for the machining of tools, generally have a fixedly disposed grinding station, next to which the workpiece which is to be machined is disposed and is held by a workpiece holder. The workpiece holder here can be a spindle head, in the rotating workpiece spindle of which the workpiece is chucked. However, the holder may also be a simple holder in which the workpiece is chucked for surface grinding.
In known universal grinding machines, the workpiece holders, such as the spindle head, the tailstock and the fixed stay for circular grinding or the clamping jaws for surface grinding, are fixed to a work table which can be moved in sliding guides on the machine bed at the grinding station. It is thereby possible to bring the workpiece into the desired position in front of the grinding wheel, or to move it along the latter so that the grinding wheel can perform the desired machining operation over the entire length of the workpiece which is chucked in the workpiece holders.
In known machines, the work table, which can be moved over its entire length, takes up considerable space, and its sliding guide on the machine bed has a considerable overall height. Even when traverse-grinding relatively thin, light workpieces, the large mass of the entire work table has to be moved. Moreover, in order to chuck workpieces of different sizes it is necessary to detach the workpiece holder from the work table each time and to re-fix it in the correct position again, so that the nonproductive time is relatively long. This is particularly disadvantageous when it is only a small number of workpieces of the same shape which are to be machined on the machine each time.